Wme strain reuever for electrical



DecQZ, 1941. s, M, KASS 2,265,073

WIRE STRAIN RELIEVER FOR ELECTRICAL FITTINGS Filed Aug. 9, 1939 Patented Dec. 2, 1941 WIRE STRAIN REIJEVER FORJELECTRICALY FITTINGS V Samuel M. Kass, Philadelphia, Pa.

Application August 9, 1939, Serial No. 289,211

4 Claims.

My present invention relates to a mechanical supporting connection between an insulated electrical lead or cable and an electrical fitting to be energized and optionally also supported from the cable. 4

A purpose of the invention is to secure a gripping connection between the outside of the supporting cable and the cable inlet ring of the fitting and without need for the gripping members to pass over the end of the cable.

A further purpose is to progressively tighten inward projections from the outer end of nipple segments upon the outside of the cable by threading the inner end of the sections into the cableinlet ring of the fitting.

A further purpose is to provide as an article of commerce externally threaded arcuate nipple segments threaded from one end and having at the other end one or more inward projections for progressively tighter engagement with the outside of a cable when progressively threading the first end of the segment into an inlet ring surrounding the cable.

A further purpose is to make the inward projections at the outer end of the externally threaded nipple segments as hooks and to mount tubular rubber or the like upon the hooks to prevent the metal projection from biting into the outer insulation of the cable.

A further purpose is to provide strain relieving segments in a, fitting with inwardly projecting prongs extended from the segments adapted to engage a cable.

Further purposes will appear in the specification and in the claims.

Figure 1 is an elevation showing a desirable embodiment of the invention applied to a light fitting to externally grip an electric cable supporting and energizing the fitting.

Figure 2 is a broken sectional plan of Figure 1 taken upon the line 2--2 of Figure 1.

Figure 3 is an enlarged fragment of the structure of Figure 1 in part section taken on the line 3-4 of Figure 2 and showing the cable in dotand-dash lines.

Figures 4 and 5 are sections of Figure 3 taken respectively upon the lines 4-4 and 5-5 thereof in the directions of the arrows.

Figure 6 is an enlarged perspective view showing one of my wedge nipple segments, as used in Figures 1 to 5.

Figure 7 is a view generally similar to Figure 6 but showing a different form.

Figure 8 is a view similar to Figures 6 and 7 but showing a modification.

Like numerals refer to like parts in all figures.

Describing in illustration and not in limitation and referring to the drawing:

In the illustrated embodiment an electrical conduit 10 supports and electrically energizes a fittinghaving a standard conduit inlet l2 with energizing inner wires l3 and I l connected at l5 and It to screw terminals of the fitting.

The fitting l l is shown as a pull-chain switch light socket but is intended for a conventional showing'of any electrical fitting, but frequently one supported from above by the conduit [0, the invention being directed to a supporting connection between the outside of the conduit l 0 and the standard conduit-inlet ring 12.

This connection comprises opposing counterpart nipple segments I! and I8.

These segments I! and I8, preferably peripherally somewhat less than semi-circumferential, are externally threaded from the lower (forward) end to fit the internal thread of the standard inlet ring [2.

At the upper or outer end each segment I! or it is provided with one or more irmer projections 19 or 20, one (I9) shown in Figures 1 to 6 and two (20) in Figure 7.

The nipple segments present their projections [9 or 20 inwardly to the outside of the cable, progressively gripping the cable as the segments are threaded progressively further forwardly into the inlet ring I2.

I prefer to make the projections l9 or 20 in the form of hooks, as shown in Figures 1 to 6, with each hook end 21 directed forwardly toward the inner end of the nipple and I may or may not according to the character of the insulation 22 upon the outside of the cable mount a non-metallic tube 23 upon the outside of the hook portion 2 l--thereby protecting the insulation of the cable from biting engagement with the metal projection 19 or 20.

In Figure 8 I have provided gripping projections 24 to the segment by slitting the segment The projections 24 are generally similar to ordinary butterfly handles which are used for screwing different objects into place.

In Figure 8 I have also shown the insulation 22 as having an apron 22 which extends downwardly approximately at full depth of the segment. This provides additional safety by insulating between the segment and the electrical conduit It).

It will be obvious that by clamping the conduit directly to the fitting the possibility of strain to the form of a cylinder section less than a half cylinder, externally threaded from one end press toward the outside of a cable and a tube of insulating material mounted on the hook and pressed against the cable.

3. A fitting having an interiorly threaded cable inlet ring to surround a cable, being spaced radially therefrom, a pair of longitudinally divided cylindrically straight metal nipples comprising arcuate segments externally threaded from their forward ends to thread into the ring on opposite sides of the cable and each segment having at its rear end an inwardly and forwardly projected hook between the segment and the cable.

' '4. A fitting having an interiorly threaded cable inlet ring to surround a cable, being spaced rato thread into a cable inlet of an electric fitting and each having at its rear end an inwardly and forwardly projecting hook adapted to press toward the outside of a cable.

2. A pair of articles comprising nipple segments having walls of .uniform thickness --shaped each to the form of a cylinder section less than a half cylinder, externally threaded from one end to thread into a cable inlet of an electric fitting and each 'having' at its rear'end an inwardly and forwardly: projecting hook adapted to dially therefrom, a pair of longitudinally divided cylindrically straight metal nipples comprising arcuate segments externally threaded from their forward ends to thread into the ring on opposite sides ofthe cable and each segment having at its rear end an inwardly and forwardly projected hook between thesegment and the cable, and a tube of insulation material mounted on the hook. and in part lying between the hook and the cable.

SAMUEL M. KASS. 

